Matthew d



Patented Feb. 5,, i924.

MATTHEW n. MANN, 3a., or ROSELLE, NEW JERSEY, AssIeNoE. r SETH B. HUNT, 'rEus'rE or MOUNT xrsoo, NEW YORK.

ART OF MANUFACTURING IS OPROPYL ETHER.

No Drawing.

To all whom it may concern:

Be it known that I, Myrrrmw D. MANN, (In, a citizen of the United States, residing at 625 Locust Street, Roselle, in the county 5 of Union and State of New Jersey, have invented a new and useful Improvement in the Art of Manufacturing Isopropyl Ether, of which the following is a specification. I The present invention relates to the man- .ufac-ture of isopropyl ether,.-and more particularly to its manufacture by the action of sulfuric acid upon isopropyl alcohol.

I have found that the acid upon isopropyl alcohol causes the de- .15 composition of the latter, with the formation of propylene in varying amounts, the strength of the acid employed being an important factor in determining the extent of decomposition. With concentrated acid 2 substantially no isopropyl ether is formed, the alcohol being decomposed, and the propylene formed polymerized to a greater or less extent.

I have determined that the decomposition of the isopropyl alcohol may be minimized by the use of diluted sulfuric, the strength of which is not above 85%. In practice, the bestresults are obtained by the use of acid of a strength between 70 and 85%, although at weaker acid may be employed, if desired. The proportion of acid to alcohol may vary greatly, since the acid is effective in its reaction upon from 1 to 5 times its' volume of alcohol. It is preferred that the reaction be as started with from 1 to 2 times the volume of alcohol present, and that if it is desired to carry on the reaction with further quantities ofalcohol, that it be added gradually as the reaction progresses. The reacting mix- 40 ture is heated to boiling point and the isopropyl ether produced passes off, accompanied by propylene and undecomposed isopropyl alcohol. If desired the latter may be refluxed to the reacting mixture. The isopropyl ether is condensed, and the propylene, which is substantially pure, may be absorbed by cold sulfuric acid with the formation of propylene sulfuric acid, which may, if desired, be hydrolyzed to form the action of sulfuric,

.say at 45 to Application filed October 27,,1921. Serial No. 510,821.

alcohol, with which the reaction may be repeated.

The following specific examplesare illustrative of the present invention:

First example.

alcohol are slowly added, preferably at a rate to maintain approximately a constant volume of reacting mixture. The yield of isopropyl ether is approximately 40% of theoretical, the decomposition of the alcohol being substantially entirely confined to the formatlon of the ether and propylene. Second example. I

1 1/2 times its volume of 90% isopropyl alcohol. The mixture is distilled through a fractionating column. The temperature of .the reacting mixture is maintained at 100 to 125 (3., and the temperature at the top of the column is maintained somewhat below the boiling point of isopropyl ether,

C. The ether is carried over by the gaseous propylene evolved. The ether is condensed and the propylene absorbed in sulfuric acid, say concentrated sulfuric acid at a temperature of 10 C. or lower. The acid extract obtained may be diluted and added directly to the reaction mixture, the proportion of water added being calculated to reduce the sulfuric acid concentration to approximately that of the mixture, or, if desired, it may be hydrolyzed and the alcohol formed added to the reaction mixture.

I claim:

1. The method of manufacturing isopropyl ether which comprises reacting upon isopropyl alcohol with sulfuric acid of a strength below 85%.

sulfuric. acid is mixed with 1 1/4 to propyl ether which comprises reacti'n 2. The method .propyl other which isopropyl alcohol with sulfuric aci of manufacturing isocomprises reactin upon of a strength between 70 and 85%.

3. The method propyl alcohol to t of manufacturing isopropyl ether which comprises subjecting isohe action of sulfuric acid of a strength between 70 and 85% and boiling the mixture.

4.. The method isopropyl alcohol strength between 7 evolved isopropyl of manufacturing isowith sulfuric aci propyl ether which sorhing the latter in sulfuric acid as'propy lene sulfuric acid and returning the latter to the reaction mixture.

5. The method of manufacturing isocomprises heatin sulfuric acid of a stren with isopropyl alco through a column, maintained somewhat below the boiling point of isopropyl ether, and se arating the 01, passing the va ors escaping vapors 1nto isopropy ether and propylene.

EW D. MANN, JR.

h between an the outlet of whic is 

